1. Field of the Invention
The present invention relates to a microscope and an optical system thereof and a virtual slide forming system and in particular to a technique for moving an observing field of view in a microscope.
2. Related Background Art
In ordinary microscope observation, after searching for a point to be observed with an objective lens having low magnification, the point is observed with enlarging by an objective lens having high magnification. However, there is a possibility of danger that a position of a sample is slipped out by an impact upon changing an objective lens.
In an example disclosed in Japanese Patent Application Laid-Open No. 2002-31758, in order to observe a wide area, the magnification of the objective lens is limited to 32 or less and to observe details with high magnification, the numerical aperture of the objective lens is set to 0.85 or more. And the objective lens and a magnification-change optical system is combined. Accordingly, without changing the objective lens, it becomes possible to observe a wide field of view by setting low magnification to the magnification-change optical system and a fine detail with high resolving power by setting high magnification to the magnification-change optical system.
However, in the method disclosed in Japanese Patent Application Laid-Open No. 2002-31758, the same position of a sample always comes to the center of the observing image whenever changing the objective lens. Accordingly, in a low magnification observation, when you find a position, which you feel like to observe with enlarging, locating away from the center of the field of view, in order to observe with high magnification, you have to bring the position near to the optical axis of the objective lens. Accordingly, the positional relation between the sample and the objective lens has to be changed, in other words, the observing field of view has to be moved.
In an ordinary upright microscope, when an observing field of view is to be moved, it has been carried out that the observer moves a stage on which the sample is placed perpendicularly to the optical axis of the objective lens or moves the objective lens.
However, in a microscope observation in a field such as electrophysiology, it may be happened that a manipulator or the like is set to a sample, so that great care has to be taken that the manipulator does not touch with the objective lens upon moving the observation field of view. Moreover, it also has to be careful that the objective lens does not touch with a tube or a channel arranged for maintaining the environment of the sample.
In an actual experiment system, the distance between the tip of the objective lens and the manipulator is extremely small (1 mm or less), so that it has been very difficult to observe without touching with each other. Moreover, when observing with an immersion-objective lens, it may happen that the interface between the objective lens and the water, being in the state of contact with each other, makes a change by moving the field of view. In this case, when the sample is vulnerable to the vibration, there is a possibility of danger that the state of contact between an electrode needle set on the tip of the manipulator and the sample or the sample itself is changed.
Accordingly, it has been demanded to provide a method to move the observation field of view without moving or changing the objective lens or without changing the position of the stage or the sample.